Hydraulic elevator



2.SheetsSheet 1. D. P. DAVIS. Hydraulic Elevators.

No. 229,591. Patented July 6, 1880.

2Sheets-Sheet 2 D. P. DAVIS. Hydraulic Elevators.

No. 229,591. Patented July 6, 1880.

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M M M I NPETERS PHOTO-MPH, WASHINGTON. D. C.

UNITED STATES PATENT OFFICE,

DAVID P. DAVIS, OF JERSEY CITY, NEW JERSEY.

HYDRAULIC ELEVATOR.

SPECIFICATION forming part of Letters Patent No. 229,591,'dated July 6, 1880.

Application filed January 17, 1880.

To all whom it may concern:

Be it known that I, DAVID P. DAVIS, of J ersey City, in the county of Hudson and State of New Jersey, have invented an Improvement in Hydraulic Elevators, of which the following is a specification.

Hydraulic elevators have been madein which there is a cylinder and piston connected by a rod and multiplying-pulleys to the car. the water being supplied at one side of the piston to raise the car, and escaping as the car is lowered, the speed of movement depending on the opening of the inlet and outlet valves, and in some instances the pressure from an elevated tank has been used, and in other instances the water has been pumped into the cylinder.

My invention, as distinguished from others, relates to transferring the water from one side of the piston to the other by the action of a pump, and keeping the passages and cylinders entirely full of water by supply from a smallreservoir that makes up loss from leakage, whereby there cannot be any vacuum or air-space, and sudden motion of the piston or the car in either direction is prevented.

I also combine with the elevator-cylinder and pump-passage ways and valves arranged in such a manner that the pump may continue to run in one direction, and by moving the valves the Water is taken from'below the piston and transferred to'the cylinder above the piston, thus moving the piston in one direction or else the water is transferred from above the piston to the cylinder below the piston, moving the piston the other way; or else the water is allowed to churn'taround in the pump and pipes without passing into the hydraulic'cylinder, and hence the piston and car are held stationary. In all these cases the power exerted will only be in proportion to the weight to be raised, because the governor of the engine will'only' supply the steam needed to run the pump at a given speed, and this speed will be maintained by a lower pressure of steam with a light load than with a heavy lead. A saving will therefore be effected by my improvement over and above the devices in which the water has to be pumped up to a given height, and there is as much Water used With a light load as with a heavy load.

My invention is also to be distinguished from those elevators in which the car is raised by a pump that is used to force the water into the hydraulic cylinder, and the lowering of the car is controlled by the escape of water into a tank; and it is also to be distinguished from elevators in which the Weight of the car in descending is made to operate a pump, the speed of which is controlled by valves that regulate the discharge of the water from the pump. I

In the drawings, Figure l is an elevation of the apparatus. Fig. 2 is an elevation at right angles to Fig. 1, without the engine; and Fig- 3 is a section at the line a: as through the valves.

The cylinder at is of suitable size, according to the character of the elevator, and the piston-rod r from the piston is connected by suitable ropes and multiplying-pulleys to the car or platform to be raised.

The engine is represented at G, and the same may be of any desired character, and the pump 1) is represented as a rotary pump. It may, however,be a double-acting pump of any character to insure uniformity in the action on the water.

The pipes f and f pass from the ends of the cylinder at to the water-ways of the pump.

'TheseWater-ways are shown more clearly in Fig. 3, wherein the valves 01 and e are introduced within cylinders at the junction of the branch pipes f from the pipe f, and J" from the pipe f, and the pipe n 'It" from the pump.

The cylindrical valves d and e are within cylindrical cases, and the stems of the valves pass through glands or stuffing-boxes. On the stem of the valve d there is a wheel, 9, that is operated by the hand-rope in the elevator, and the connecting-rod h and crank 71/ to the stern of the valve 6 operate so that the two cylinder-valves are moved at the same time by the elevator-rope. There is a pipe, 2, passing from the valve-cylinder d to the valve-cylinder 6; v The induction-way it passes from the inside of the cylinder-valve e to the pump, and the eduction-pipe n terminates in the cylinder-valve d.

The action is as follows: When the valves d and e are in the positions shown in Fig. 3 the water passing from the pump goes along it into 01, thence by the ports 1 2, pipe t', and

ports34,into the valve 0 and back to the pump. At this time the cylindrical valves close (I and e, the ports 5, 6, 7, and S, and water cannot pass by the pipes for f, and the cylimler of water is quiescent, and holds the elevator car or platform stationary. \Vhen the elevatorrope is moved and the valves (I 0 turned so as to bring the ports 9 and 5 and 8 and 12 opposite to each other, the wateris drawn from the top of the cylinder by the pipef to the valve 6 and induction 1:, and the water is forced from the pump by n, d, J, and 5, into the pipe f, and the lower end of the cylinder, and the piston is moved upwardly. When the elevator-rope is so moved as to turn I? and 4' to bring the ports 7 and 11 aml 10 and (5 together the water is forced from (I through f, and drawn from f through 7 and 11 into c, and thence by 'n to the pump. By this arrangement the hoisting, lowering, and sustaining ot' the ele' vator are entirely under control of the attendant, and the pump will run continuously.

As a precaution to prevent injury, it the cylinder-valves are not turned the proper distance I employ a pipe, 0, connecting the water-ways n and 'n', and in this pipe 0 there is a safety-valve, p, preferablyoperated by a spring that yields and allows the water to churn around through the pump it the maximum pressure is exceeded.

I remark that the cylimler-valves 11 and e are preferred but slide or puppet valves may be used in place of the cylinders, the ports being arranged, in connection with the water-ways, so as to efl'ect the same movement of the water by the pump.

The reservoir k is above the pipef, leading from the lower side of the cylinder, and a pipe and valve, I, connect the reservoir to the pi pef. This valve should open automatically by any minus pressure; hence, if there is any leakage of water, the deficiency will be supplied by water drawn in from said reservoir It, so as to keep lhe cylinder and waterways all full.

I am aware that air has been forcedinto the hoistway below the car to raise it, or allowed to pass above the car as it descends, and that a valve has been operated from the car to direct the air.

I claim as my invention- 1. The combination, with the hydraulic-elevator cylinder and piston of a pump, waterways and valves arranged and acting, substantially as set forth, to transfer the water from one side of the elevator-piston to the other and move that piston in either direction, or to allow the water to be confined, and a connection from the outlet to the inlet of the pump, whereby the pump continues its movement when the elevator is stationary, as set forth.

.2. The combination, with the elevator cylin der and piston, of the watcr-waysf f f f, valves 11 e, connecting-pipe 0', pump, and mechanism connecting the valves d and c with the hand rope ot the elevator, substantially as set forth.

3. The combination, in an elevating apparatus, of the hydraulic cylinder a, pump, water-ways connecting the cylinder and )nmp, valves in those waterways, constructe and acting substantially as set forth, and a reservoir and inlet-valve to supply water and compensate leakage, as set forth.

Signed by me this 14th day of January, A. l). 1880.

DAVID P. DAVIS.

\Vitnesses:

GEo. T. PINGKNEY, WILLIAM G. MO'IT. 

